Pacific Gas and Electric Co. can safely restore pressure on a natural-gas line in San Carlos that had been virtually shut down since an internal e-mail questioning its integrity became public, a regulatory judge with California Public Utilities Commission said Friday.

The judge, Maribeth Bushey, said she was satisfied by PG&E assurances and findings by commission staffers that the gas transmission line was "fit for service." She said the company could boost pressure on the line to 330 pounds per square inch, close to its maximum capacity.

Bushey's recommendation is expected to go before the five-member utilities commission Dec. 19.

The commission ordered pressure on the 3.8-mile line to be cut to less than half its capacity in October after San Carlos officials went to court, citing a November 2012 e-mail written by one of PG&E's consultants, David Harrison. In it, he told company executives that the line could pose the risk of "another San Bruno situation."

The problem, Harrison wrote, was that PG&E work crews repairing the line had discovered that it had several 1920s-vintage welds of a type that has been linked to pipe failures nationwide. The company's records did not reflect the welds' presence, he noted - a similar problem to the situation in San Bruno before a pipe ruptured there in September 2010, causing a blast that killed eight people and destroyed 38 homes.

Harrison testified before Bushey last month that although he stood by his original concerns, he was now satisfied that PG&E had addressed the problem and that the pipeline was safe.

Bushey also cited testimony by PG&E experts that the line could safely operated at 330 pounds per square inch, the level to which the company had cut it last year after it discovered its faulty records.

A PG&E spokesman, Greg Snapper, called Bushey's decision "very timely ... given the cold snap in the Bay Area." He said natural-gas demand Thursday was greater than on any day in the company's 108-year history.

There was no immediate reaction from San Carlos officials.

PG&E still faces as much as $17 million in fines for not telling the state of its discovery of the flawed records for several months. The utilities commission is expected to consider a penalty at its Dec. 19 meeting in San Francisco.